code: def _extract_act_pos(acts, x=None, y=None):
      shape = tf.shape(acts)
      x_ = shape[1] // 2 if x is None else x
      y_ = shape[2] // 2 if y is None else y
      return acts[:, x_ : x_ + 1, y_ : y_ + 1]
  
file_path: lucid/lucid/optvis/objectives_util.py
imports: from __future__ import absolute_import, division, print_function
  from decorator import decorator
  import numpy
  import tensorflow
  import lucid.misc.graph_analysis.property_inference
label_desc: Use image node_id 3 for calling a global function with example usage: _extract_act_pos(acts, x, y) and returns: acts